Brake pad assembly with lining carrier that has an internal axial elasticity

Abstract

The invention relates to a brake pad assembly (10) for a vehicle disc brake (11), the brake pad assembly (10) comprising a lining carrier (12) and a brake lining layer (14) attached to the lining carrier (12), wherein the lining carrier (12) has a first portion and a second portion which are connected by at least one connecting portion (20) forming at least part of a side face (21) of the lining carrier (12), wherein the connecting portion (20) is elastically deformable upon braking.

Claims

1. A brake pad assembly (10) for a vehicle disc brake (11), the brake pad assembly (10) comprising a lining carrier (12) and a brake lining layer (14) attached to the lining carrier (12), wherein the lining carrier (12) has a first portion (16) and a second portion (18) which are connected by at least one connecting portion (20) forming at least part of a side face (21) of the lining carrier (12), wherein the connecting portion (20) is elastically deformable upon braking.

2. The brake pad assembly (10) according to claim 1, wherein the elastic deformation includes compressing the connecting portion (20) along a deformation axis (D) which is orthogonal to a contact surface (15) of brake lining layer (14) for contacting a brake disc (25).

3. The brake pad assembly (10) according to claim 2, wherein said connecting portion (20) has at least one section (22) extending at an angle to said deformation axis (D), said angle being variable when elastically deforming the connecting portion (20).

4. The brake pad assembly (10) according to claim 2, wherein said connecting portion (20) is configured to move the contact surface (15) towards a position before braking upon releasing the vehicle disc brake (11).

5. The brake pad assembly (10) according to claim 1, wherein the connecting portion (20) forms at least half of a length (L) of the side face (21).

6. The brake pad assembly (10) according to claim 1, wherein at least two connecting portions (20) are provided and at least partially form different side faces (21) of the lining carrier (12).

7. The brake pad assembly (10) according to claim 1, wherein at least the connecting portion (20) extends circumferentially, thereby forming part of different and in particular of all side faces (21) of the lining carrier (12).

8. The brake pad assembly (10) according to claim 1, wherein the connecting portion (20) has a linear deformation characteristic with respect to an expected spectrum of forces applied during braking.

9. The brake pad assembly (10) according to claim 1, wherein the lining carrier (12) comprises at least a first member (30) comprising the first portion (12) and a second member (32) comprising the second portion (18), the first and second member (30, 32) being connected to one another within the connecting portion (20).

10. The brake pad assembly (10) according to claim 9, wherein the first member (30) and the second member (32) engage each other in the connecting portion (20).

11. The brake pad assembly (10) according to claim 9, wherein the first member (30) and the second member (32) are each formed as a sheet metal bending part.

12. The brake pad assembly (10) according to claim 1, wherein the lining carrier (12) comprises guiding projections (24) for being received in a brake caliper of the vehicle disc brake (11), the guiding projections (24) being arranged at the second portion (18).

Description

[0056] Embodiments of the invention are described in further detail below with respect to the attached schematic figures. Same features may be marked with the same reference signs throughout the figures.

[0057] FIG. 1 is a perspective view of a brake pad assembly according to first embodiment of the invention.

[0058] FIG. 2 is a partial top view of a brake pad assembly according to second embodiment of the invention with the brake being released.

[0059] FIG. 3 is a view similar to FIG. 2 with the brake being activated.

[0060] FIG. 4 is a partial top view of a brake pad assembly according to third embodiment of the invention with the brake being released.

[0061] FIG. 5 is a view similar to FIG. 4 with the brake being activated.

[0062] FIG. 1 is a perspective view of a brake pad assembly 10 according to a first embodiment. The illustration is highly schematic and the depicted shapes and sizes are merely exemplary. The brake pad assembly 10 is configured to be mounted to a vehicle disc brake 11 that is not specifically illustrated and that is configured according to known solutions. Selected components of the vehicle brake assembly 11 are shown in FIGS. 2-5 (see brake disc 25 and brake piston 26).

[0063] The brake pad assembly 10 comprises a lining carrier 12 that can also be referred to as a backplate. At a front face of the lining carrier 12 which faces the viewer, a brake lining layer 14 is arranged. By way of example, the brake lining layer 14 has a rectangular shape. Its front face facing the viewer is a contact surface 15 which can be brought into contact with a non-depicted brake disc of the vehicle disc brake 11.

[0064] For doing so, the brake pad assembly 10 is axially displaceable along and in parallel to an axis R. This axis R is a rotational axis about which the brake disc rotates. When releasing the brake, the brake pad assembly 10 is displaced in an opposite direction along the axis R in order to lift the brake lining layer 14 off the brake disc. This is discussed in further detail with respect to the subsequent FIGS. 2-5.

[0065] In FIG. 1, as a mere simplification, a thickness of the brake lining layer 14 along the axis R is not specifically illustrated.

[0066] The lining carrier 12 comprises two portions 16, 18. These extends in parallel to one another as well as in parallel to the brake lining layer 14. More precisely, each of the first portion 16 and second portion 18 are substantially flat and/or plate-shaped. Their respective planes extend substantially in parallel to the brake lining layer 14 (in particular to a rear surface thereof that is attached to the lining carrier 12).

[0067] The second portion 18 (and more precisely a rear surface thereof facing away from the viewer) contacts a non-illustrated brake piston (see also following FIGS. 2-5). In a generally known manner, the brake piston can exert a brake force onto said rear surface, thereby pushing the brake pad assembly 10 along the axis R and bringing the contact surface 15 of the brake lining layer 14 into contact with the brake disc. When releasing the brake, the brake piston ceases to exert respective forces and an elastic restoring force discussed below pushes the brake pad assembly 10 back into its original position.

[0068] The first and second portion 16, 18 are connected to one another by a connecting portion 20. Said connecting portion 20 forms an (in FIG. 1) radially upper side face 21 of the lining carrier 12. Preferably, more than one side face 21 of the lining carrier 12 comprises or is at least partially formed by a similar connecting portion 20 (not shown). For example, at least the opposite radially lower side face 21 is likewise formed by a similarly configured connecting portion 20. The brake pad assembly 20 also has two further side faces 21, namely a left and right one in FIG. 1, that connect said radially upper and lower side face.

[0069] If all side faces are formed by a respective connecting portion 20, a continuous circumferentially extending connecting portion may be provided. Yet, at least corner portions at which two side faces 21 merge or are directly adjacent to one another may be free of a respective connecting portion 20.

[0070] The connecting portion 20 (and any further non-depicted connecting portion 20) is an elastically deformable portion of the lining carrier 12 that provides a dedicated reduced axial stiffness of the brake pad assembly 10. Specifically, the lining carrier 12 is elastically and axially compressible by deforming said connecting portion 20, thereby altering an axial distance between the first and second portion 16, 18.

[0071] Merely as an example, the connecting portion 20 is formed as an elongated and inwardly bent or inwardly kinked portion. It has a V-shaped cross-section comprising two angled sections 22 each forming a leg of said V-shape. Each angled section connects to one of the first and second portion 16, 18 and connects to the respective other angled section. The angled sections 22 may also be referred to as planar or elongated flaps. They extend at an angle to the axis R.

[0072] When pushing the brake pad assembly 20 against the brake disc, an axial compression force acts on the connecting portion 20. The connecting portion 20 is elastically deformed by said force. Specifically, its angled portions 22 will change their orientation and e.g. assume a more upright orientation relative to the axis R. As a result, an axial distance between the first and second portion 16, 18 is reduced and the connecting portion 20 is generally axially compressed. This compression takes place along a deformation axis D that extends in parallel to the rotational axis R.

[0073] When releasing the displacing force, the connecting portion 20 elastically relaxes and, by way of an elastic resetting force, returns to its original shape. That is, the angled sections 22 return to their less upright orientation depicted in FIG. 1 while increasing the axial distance between the first and second portion 16, 18.

[0074] As further evident from FIGS. 2-5, this also means that the contact surface 15 of the brake lining layer 14 pushes off the brake disc due to the stored elastic deformation energy being released. Thus, the desired clearance between the brake lining layer 14 and brake disc is established.

[0075] The depicted connecting portion 20 has a substantial length L of several centimeters. Said length L is measured in a plane that is orthogonal to the axis R. Due to said large length L, the elastic resetting forces can be exerted along the complete brake lining layer 14 to increase uniformity of the established clearance.

[0076] Specifically, the brake lining layer 14 and in particular its contact surface 15 has a width dimension W and a height dimension H extending orthogonally to one another. The height dimension H extends substantially radially, e.g. defining a distance between a radially upper and radially lower of the brake lining layer 14. The width dimension W defines a distance between a left and right edge of the brake lining layer 14. The width dimension W also extends in between two guiding projections 24 that are configured as generally known hammer-head projections.

[0077] In the shown example, the length L of the connecting portion 20 is substantially the same as the width dimension W. Generally, it preferably amounts to at least half of said width W. In case similar connecting portions 20 are provided at the right and/or left side faces 21, their length L (which is oriented similar to the height dimension H) preferably amounts to at least half of said height H.

[0078] The depicted embodiment advantageously integrates an elastic resetting function directly into the lining carrier 12 by way of the at least one elastically deformable connecting portion 20.

[0079] FIG. 2 depicts a top view of a brake pad assembly 10 according to a second embodiment. As evident form the orientation of the axis R (which again is a rotational axis of a brake disc 25), a viewing axis thus extends radially and a radially upper side face 21 faces the viewer. The displacement axis D is thus overlaid with the rotational axis R.

[0080] Only by way of example, no connecting portion 20 is provided at said upper side face 21, but there may be a connecting portion that is e.g. configured according to FIG. 1 or that is similar to the connecting portions 20 of this second embodiment (see below).

[0081] Again, the left and right guiding portions 24 are shown. Also, a brake piston 26 is depicted that is connected to (e.g. mechanically fixed to) a rear surface of the brake lining carrier 12.

[0082] In this second embodiment, the brake lining carrier 12 is configured as a multi-part unit. Specifically, the first portion 16 at which the brake lining layer 14 is arranged is comprised by a first member 30. The second portion 18 that contacts the brake piston 26 is comprised by a second member 32.

[0083] For the purpose of illustration only, the first and second member 30, 32 are illustrated with different line widths. These line widths are not meant to indicate a material thickness of the respective members 30, 32. Said members 30, 32 can be provided with similar material thicknesses. Also, the second member 32 can be made form a thicker sheet metal than the member 30, and vice versa.

[0084] Each of the first and second member 30, 32 are configured as sheet metal bending parts. From their respectively planar first a second portions 16, 18, connecting sections 34 are angled so as to protrude towards the respective other one of the first or second member 30, 32.

[0085] Merely as an example, these connecting sections 34 are only provided at left and right outer edges of the members 30, 32. They can also be provided, additionally or alternatively, at their radially upper and lower edges.

[0086] The exact shape and dimensions of the connecting sections 34 can differ from the schematically depicted example. In the shown example, the connecting section 34 of the first member 30 forms a receiving portion, whereas the connecting section 34 of the second member 32 forms a projecting portion that is inserted into said receiving portion. This way, the connections sections 34 and thus the members 30, 32 can be brought into engagement with one another.

[0087] In addition or alternatively to said engagement or form-fit, a more permanent connection by way of gluing or welding can be provided.

[0088] Again, the connection between the first and second portion 16, 18 and more specifically between the members 30, 32 comprising said portions 16, 18 is made at or within a side face 21 of the lining carrier 12. That is, the above-discussed connection between the connecting sections 34 forms left and right connecting portions 20 that represent left and right side faces 21 of the lining carrier 12.

[0089] Each connecting portion 20 extends orthogonally to the image plane and thus along the height dimension H of the brake lining layer 14 (see FIG. 1). Again, a length of each connecting portion 20 may be equivalent to or amount to at least half of said height dimension.

[0090] Further, by extending orthogonally to the image plane, it is evident that the connecting sections 34 each have an elongated flap shape.

[0091] In FIG. 2, the brake is not activated and the brake piston 26 does not exert an axial force onto the brake pad assembly 10. Therefore, the brake lining layer 14 remains at a distance from the brake disc 25 so that no brake effect is produced. A respective clearance or gap is marked by the reference sign G in FIG. 2.

[0092] Further, the connecting portions 20 are each undeformed. Their connecting sections 34 extend at angles to the axis R and assume orientations given to them during initial production and when not under load.

[0093] FIG. 3 shows the piston 26 exerting a braking force onto the rear surface of the second member 32 (see arrow in FIG. 3). The brake assembly 10 is thus moved along the axis R and the brake lining layer 14 is forced into contact with the brake disc 25 to generate frictional braking forces.

[0094] As a result, the connecting portions 20 are elastically deformed. Specifically, they are axially compressed so that a distance between the parallel front and rear surfaces of the first and second member 30, 32 is slightly reduced. Further, their connecting sections 34 are at least partially deformed by being elastically bent. This results in a change of orientation e.g. with respect to the axis R. For example, it can be seen that the connecting sections 34 become more upright with respect to said axis R.

[0095] When releasing the brake, hydraulic pressure is released from the brake piston 26 which thus ceases to exert the pushing force onto the brake pad assembly 10. This means that the stored elastic deformation energy is set free. More precisely, an axial elastic restoring force of the bent connecting sections 34 pushes the brake pad assembly 10 off and away from the axially stationary brake disc 25. In order to be able to so, the connecting sections 34 are e.g. sized, orientated and made from a suitable material, so that the elastic restoring forces exceed a frictional resistance between the guiding projections 24 and the non-depicted brake caliper.

[0096] The brake pad assembly 10 is thus axially displaced to return to its original position of FIG. 2. The gap G is restored. The connecting sections 34 return to their original undeformed orientation.

[0097] FIGS. 2 and 3 also show that the guiding projections 24 are arranged at a common one of the first and second member 30, 32 (in the shown example at the second member 32).

[0098] Further, it is evident that the lining carrier 12 encloses an internal hollow space 40. As previously discusses, a noise dampening material may be arranged in said space 40.

[0099] FIGS. 4 and 5 show an embodiment that is largely similar to that of FIGS. 2 and 3. The only difference is the configuration of the connecting sections 34. Compared to the second embodiment, their positioning is reversed in that now the second member 32 has the connecting sections 34 forming a receiving portion. Further, the first member 30 now has the connecting section 34 inserted into said receiving portion. The general operation of the brake pad assembly 10 and its elastic restoring effect is similar to that of the second embodiment.

LIST OF REFERENCE SIGNS

[0100] 10 brake pad assembly [0101] 11 vehicle disc brake [0102] 12 lining carrier [0103] 14 brake lining layer [0104] 15 contact surface [0105] 16 first portion [0106] 18 second portion [0107] 20 connecting portion [0108] 21 side face [0109] 22 angled section 8 of connecting portion) [0110] 24 guiding projection [0111] 25 brake disc [0112] 26 brake piston [0113] 30 first member [0114] 32 second member [0115] 34 connecting section [0116] 40 space [0117] L length [0118] H height [0119] W width [0120] R rotation axis [0121] D deformation axis